All cataract and dermatology operations have been cancelled at Maisonneuve-Rosemont Hospital because of air quality issues.
Hospital administrators have been scrambling to move or re-schedule surgeries this week after air quality tests showed a high level of dust in the air as a result of some recent renovations.
Radio Canada says about 50 cataract surgeries and dermatology operations have been moved to other hospitals or to private clinics.
The problem has been traced to the ventilation system and some surgeries will resume tomorrow.
Hospital officials say the issue should be completely resolved by next week